This invention pertains to a catalyst rejuvenation vessel assembly and a method for rejuvenation treatment of particulate used catalysts. It pertains particularly to such a rejuvenation vessel assembly and method for used catalyst rejuvenation in which solvent washing, acid-treatment, water washing, and drying steps for used catalysts are all performed successively in the single vessel, followed by withdrawal of the rejuvenated catalyst from the vessel.
Regeneration of used particulate catalysts from hydrocarbon catalytic processing operations to remove carbon and metal compounds deposits from the catalyst is known and usually uses multiple vessels for accomplishing the catalyst treatment. For example, U.S. Pat. No. 4,287,088 to Sirkar discloses a concentric vessel arrangement for used catalyst treatment by flotation and segregation of the particles. Also, U.S. Pat. No. 4,454,240 to Ganguli discloses process steps for acid treatment of used catalyst to remove metals compounds deposited thereon which uses several different vessels sequentially. Although such equipment and processes have been found useful for regeneration of used catalysts, it would be desirable to provide an improved single vessel unit arranged for advantageously performing any or all the catalyst washing, treating and drying functions successively in the same vessel. However, such a catalyst rejuvenation vessel arrangement has evidently not previously been developed suitable for commercial use.